There are all sorts of reasons I should have hated "Quarantine."

It’s a remake of the Spanish film "[Rec]," (released less than a year ago!), making it yet another American re-do of a foreign horror movie. It cops "The Blair Witch Project" by presenting the story as if we’re watching found footage that is the only record of mysterious killings. And it takes its handheld, real-time camera style straight out of "Cloverfield."

But despite all that, most of "Quarantine" works surprisingly well.

The fun begins when television reporter Angela (Jennifer Carpenter) and her cameraman Scott (Steve Harris) spend the night at a Los Angeles fire station to capture what it’s like to be a firefighter. We watch Angela interview several firefighters and generally witness the camaraderie among men who work 48-hour shifts together.

It all seems off-the-cuff and it’s trivial enough to create a nice sense of realism. It’s also in the form of unedited video footage that includes gaffes and behind the scenes moments, as if someone had taken the tape directly out of a camera. Again, nothing new, but effective nonetheless.

The tone changes abruptly when the firefighters respond to a call at an apartment building. They find all the residents in a stir because of screams coming from an elderly woman’s apartment.

The firefighters, two cops on the scene, and Angela all assume the woman is having major health problems. We viewers know better. The woman actually is the first monster of our little scream fest. She is inflicted with some sort of virus (so "Quarantine" also knocks off "28 Days Later" and lots of other movies), which spreads rapidly throughout the building.

SWAT teams and the Centers for Disease Control and Prevention lock down the building, putting everyone inside under (say it with me) quarantine. So the uninfected people fight off the bloodthirsty infected people, all captured by our news cameraman.

Up to a point, "Quarantine" is like walking through a good haunted house: We know the tricks about to be played on us, but we scream and laugh anyway, because that’s why we’re there. It’s all in good fun, and we appreciate how the minimum-wage earners and volunteers in the place are trying so hard to show us a good time.

If only the movie didn’t end as it does. No spoilers here, but viewers will be extremely divided on the final act.

The most impressive thing about "Quarantine" is that in order to maintain the sense that we’re watching raw video footage, much of the film had to be shot with long takes. Most shots last for several minutes. Once the scary stuff begins, each shot includes chases up and down stairs, running into and out of rooms and multiple attacks, all done without the aid of editing. Any filmmaker knows these things are very hard to pull off, and "Quarantine" does it well enough to compensate for most of its weaknesses.

Horror fans should enjoy the movie almost as much as they will enjoy debating which is better: "Quarantine" or its source material, "[Rec]."